Search results for "DIRECTION"
showing 10 items of 343 documents
Pannello precompresso di vetromattoni assemblati a secco per la realizzazione di involucri traslucidi
2012
L’invenzione riguarda la realizzazione di un pannello di vetromattoni montati “a secco” -da impiegare per la realizzazione di involucri edilizi traslucidi anche nel caso di edifici alti- che è in grado di rispondere adeguatamente alle sollecitazioni orizzontali (quali quelle dovute a vento e sisma) grazie all’applicazione della tecnica della precompressione mondirezionale. Per offrire una risposta ai limiti imposti dalla tecnica di assemblaggio tradizionale dei vetromattoni (“ad umido”), l’applicazione della precompressione consente, infatti, di dare ai pannelli preassemblati “a secco” una rigidezza adeguata anche in direzione normale al loro piano di posa, sfruttando le buone caratteristic…
Three-dimensional analysis of load transfer micro-mechanisms in fibre/matrix composites
2009
International audience; This study gives a detailed analysis of load distributions around fibre breaks in a composite. In contrast to other studies reported in the literature, the analysis considers different configurations of composite damage from the failure of a few to the failure of many fibres. The model considers three types of matrix behaviours (elastic, elastic–plastic and viscoelastic) with or without debonding at the broken fibre/matrix interface. In this way, the usual limitations of the finite element approach are overcome so as to take into account the number and interactions of broken fibres whilst maintaining an evaluation of the various fields (stresses in particular).
Variational formulations and extra boundary conditions within stress gradient elasticity theory with extensions to beam and plate models
2016
Abstract The principle of minimum total potential energy and the primary principle of virtual power for stress gradient elasticity are presented as kinematic type constructs dual of analogous static type principles from the literature (Polizzotto, 2014; Polizzotto, 2015a). The extra gradient-induced boundary conditions are formulated as “boundary congruence conditions” on the microstructure’s deformation relative to the continuum, which ultimately require that the normal derivative of the stresses must vanish at the boundary surface. Two forms of the governing PDEs for the relevant boundary-value problem are presented and their computational aspects are discussed. The Timoshenko beam and th…
Tuneable multicoloured patterns from photonic cross-communication between cholesteric liquid crystal droplets
2014
Monodisperse droplets of planar-aligned cholesteric (N*) liquid crystal exhibit an intriguing capacity for photonic cross-communication, giving rise to colourful patterns that depend sensitively on the N* pitch, droplet positions and illuminated area. The phenomenon results from a combination of omnidirectional selective reflection of N* droplets—which thus act as spherically symmetric self-assembled photonic crystals—and total internal reflection at the continuous phase surface. We outline how the unique optical properties can be employed in numerous applications.
Identifying gene-environment interactions in schizophrenia: contemporary challenges for integrated, large-scale investigations
2014
European Community Recent years have seen considerable progress in epidemiological and molecular genetic research into environmental and genetic factors in schizophrenia, but methodological uncertainties remain with regard to validating environmental exposures, and the population risk conferred by individual molecular genetic variants is small. There are now also a limited number of studies that have investigated molecular genetic candidate gene-environment interactions (G x E), however, so far, thorough replication of findings is rare and G x E research still faces several conceptual and methodological challenges. in this article, we aim to review these recent developments and illustrate h…
Micromechanisms of load transfer in a unidirectional carbon fibre-reinforced epoxy composite due to fibre failures: Part 3. Multiscale reconstruction…
2008
International audience; This third article describes a multiscale process which takes into account the most important microscopic phenomena associated with composite degradation, including fibre fractures and interfacial debonding, overloading of fibres neighbouring a fibre break as well as viscoelastic behaviour of the matrix. The results have been used to accurately predict the macroscopic failure of unidirectional carbon fibre-reinforced epoxy and quantify damage accumulation in pressure vessels made of the same material. The approach described has allowed the acoustic emission activity resulting from fibres breaks to be evaluated and shown how the residual lifetimes of such vessels, whe…
Evaluation of the effects of different groove length and thickness of the retainers on the retention of maxillary anterior base metal resin bonded re…
2012
Objectives: The resin-bonded fixed partial dentures have gained immense popularity in recent years as they are more conservative, esthetic, economic and easily fabricated. However debonding is considered the most common cause of failure of resin bonded prosthesis. The objective of the study were to compare the effects of different groove lengths and thickness of retainers on retention of maxillary anterior base metal resin bonded retainers. Study Design: Twenty five metal dies of maxillary central incisor duplicated from pure typhodont teeth (maxillary left central incisors) prepared to receive retainer for resin bonded fixed partial denture having different test designs were made. Five tes…
Hiperkompetitivitātes ietekme uz stratēģisko plānošanu mūsdienu biznesa vidē; Patēriņa elektronikas mazumtirdzniecības nozares analīze
2018
Pārbaudes pamatojums izriet no pētnieku argumentiem, ka efektīva un efektīva uzņēmējdarbības stratēģija ir būtisks instruments, ko organizācijas izmanto, lai novirzītu uzņēmējdarbību no arvien mainīgās uzņēmējdarbības vides un reģistrētu pastāvīgu uzlabotu veiktspēju. No šīs pieejas tiek piedāvāts konceptuālais satvars uzņēmējdarbības vides un hiperkonkurētspējas attiecināšanai uz uzņēmumu izmantotajām stratēģijām, kāda ietekme tas ir uz stratēģisko plānošanu. Promocijas darba mērķis ir analizēt hiperkonkurences vides spiediena stratēģiskās plānošanas darbību un atrast problēmas, kas varētu rasties nākotnē. Lai atrastu atbildi uz galveno darba tēmu: analizēt stratēģiskās plānošanas rīcību h…
Uzņēmuma SIA "GELVORA" stratēģiskās attīstības virzieni.
2016
Bakalaura darba tēma ir uzņēmuma SIA „Gelvora” stratēģiskās attīstības virzieni. Darba izvirzītā problēma ir stratēģiskās attīstības plānošanas trūkums uzņēmumā SIA “Gelvora”. Bakalaura darba mērķis ir, veicot uzņēmuma stratēģiskās attīstības analīzi, noteikt attīstības virzienu ārpustiesas parādu piedziņas uzņēmumam SIA „Gelvora” un uz tā pamata izstrādāt priekšlikumus tālākai uzņēmuma attīstībai. Bakalaura darbā tika veikta SIA „Gelvora” darbības analīze piecu gadu griezumā, sākot ar 2011. gadu. Pētījums parāda, ka uzņēmums ierindojas līderu grupā un ir konkurētspējīgs savā nozarē, taču, lai uzņēmums varētu uzlabot savus darbības rādītājus, tam ir nepieciešams pieņemt lēmumu par stratēģis…
Simulation investigations of the position of Fatigue Fracture Plane in materials with biaxial loads
1989
In the paper three methods of determination of the expected fatigue fracture plane position under random triaxial stress state have been presented. They are: weight function method, variance method and damage cumulation method. The weight function method for biaxial cyclic loadings has been analysed with digital simulation. The fatigue fracture plane position has been determined with mean values of the direction cosines of principal stress axes. Averaging has been done at angle values with use of weights. Eleven various weights have been presented and their usability has been analysed on the basis of experimental results obtained by Rotvel, and Nishihara-Kawamoto. The weights with good agre…